Injection pump



June 28, 1949. R, C, GRQVES l 2,474,396

INJECTION PUMP l l i GHOruQlS June 28, 1949.

R@ cGRovEs INJECTION PUMP 4 Sheets-Sheet 2 Filed March 1. 1945 ffl Awlil,

R. C. G-ROVES INJECTION PUMP `lune 28, 1949.

Filed March 1, 1945 June 28, 1949. R. c. GRovEs 2,474,396

INJECTION PUMP Filed laren 1, 1945 v 4 sheets-sheet 4 Bu w f y GttomegsPatented June 1949 INJECTION PUMP Ronald C. Groves, Detroit, Mich.,assigner to General Motors Corporation, Detroit, Mich., a col'- porationof Delaware Application March 1, 1945, Serial No. 580.347

' (ci. ros-41) s claims. 1

The present invention generally relatesto fuel injection pumps forinternal combustion engines and more particularly relates tomulti-plunger pumps, each of which `supplies fuel to more than oneengine cylinder.

In conventional pumps of this type a valve operating in timedrelation'to the pump plungers cooperates with a common fuel inlet andrelief passage to control the fuel enteringl and relief of pressure fromeach plunger pump. On account of the difference in fuel inlet andpressure relief ilow velocities in the common passage and past thecontrol surfaces of the control valve, partv of the fuel and vapordischarged from one pump re-enters another pump with this arrangement.This prevents complete lling of the pumps with fuel and thereby preventsaccurate metering vof fuel to the engine cylinders supplied with fuelfrom each pump.

The principal object of the present invention is to provide a largearea'fuel inlet passage having fuel directing and vapor separating meansand a vent for the vapor separated, a plurality of pump cylinders eachhaving a fuel inlet check valve connected to the inlet passage, separatedelivery and by-pass or relief ports, a plunger cooperating successivelywith the delivery ports and a control valve rotatable in timed relationwith the pump plungers and axially displaceable for cooperating witheach of the cylinder relief ports in order to accurately control theamount of fuel delivered by each pump plunger to different engineworking cylinders.

Another object is to provide a lubricating pump as part of the fuel pumpassembly to supply oil to the pumps and pump operating means to properlylubricate the parts and prevent fuel leakage past certain parts therebypreventing wear of the parts and enabling them to operate at high speedeven when gasoline is used as fuel. Another object is to providesuitable lubricating and fuel sealing means to prevent leakage of fueland dilution of the oil by the fuel.

The means by which these objects are accomplished and other features ofthe inventionwill become apparent by reference to the following detaileddescription and drawings illustrating one modification of the invention.

Figure 1 of the drawings is a reduced vertical sectional view of thepump assembly, taken substantially on line I-I of Figure of thedrawings, with parts broken away to show certain of the details of theinvention to better advantage.

Figure 2 is an enlarged top plan view of the 2 assembly with partsbroken away to show certain details of the control elements.

Figure 3 is a' partial enlarged transverse sectional view takensubstantially on line 3 3' of Figure l. Y I

Figure 4 is a partial vertical sectional view taken substantially online 4-4 of Figure 2.

Figure 5 is a partial enlarged transverse sectional view takensubstantially on line ii-S of Figure 1 with parts broken away.

Figure 6 is an enlarged vertical sectional view taken on line 8l ofFigure 2.

Figure 7 is an enlarged vertical sectional view taken on line 1-1 ofFigure 5 with parts broken i Figure 8 is a vertical sectional view takenon line 8--8 of Figure 5 with parts broken away.

Figure 9 is a partial enlarged view of the control valve shown in Figurel.

Figure l0 is a sectional view taken on line illi0 of Figure 9.

Figure 11 is a circular timing diagram showing the sequence of eventstaking place in one pump for one revolution of the pump operating means.

The pump assembly is best shown in Figure l.

The assembly includes a two-part housing comprising an upper cylindricalpump housing I, provided with an upper cap or head 3 and a lowercylindrical housing I provided with a lower cap 1 having a mountingflange 9 for support on a suitable bracket, not shown, provided on aninternal combustion engine. Suitable studs II are shown extendingthrough longitudinal holes in the caps and housings with nuts I3 on oneend to hold these parts together. Suitable gaskets are providedbetweenthe housings and caps to prevent entrance of dirt into andleakage of fuel and lubricant out of these parts.

area and a seat on which an inlet valve 23 is biased by means of aspring 25. The spring permits the valve to move of! its seat so thatfuel' enters the pumping space 21 below the valve at relative lowvelocity when the. pressure therein is reduced below that of thepressure in an annular fuel inlet cavity provided in the upper hous--ing cap 3 into which the openings 2I'in each linner annular portions. lcauses the entering fuel to be directed downwardly `atraen of the v alvecages open, as best shown in Figures 1 and 3. Fuel is supplied underpressure through a fuel supply pipe 30 connnected between a fuel i inletopening 3| in the cap 3, shown extending downwardly into the annularfuel inlet cavity 29, and a suitable fuel supply pump and fuel tank, notshown. A perforated baille 33 of cylindrical shape provided with adeilecting lip '35 extending part way around thefel inlet opening 3l isincluded in the cavity 29 to divide it into outer and The deflecting lip35 into the bottom of the inner annular cavity portion and the fuel andany vapor therein flows upwardly and outwardly through the perforationsin the baille to the upper extremityof the outer annular cavity portionthereby :causing a separation of the vapor from the fuel. Suitableinterconnected venting passages 31, 39 in the cap 3 are shown in Figure1 opening into these two annular inlet cavity portions; 'A restrictedventing orifice 4| is included in the venting passage 31 and a returnpipe 43 is connected to this passage for continuous return of any vaporand fuel to the fuel tank.

Each pump cylinder sleeve l1, as best shown in Figures 1 and 4 isprovided with two axial and angularly spaced high pressure fuel deliveryports 44, 45 near the top and a by-pass or relief port 41 below thedelivery ports. Each of the delivery ports open into a separate deliverypassage in the pump housing I. These delivery passages are indicated bythe numerals 49 and 5|. An outwardly opening check valve 53 is includedin each of these passages, as best shown in Figure 4.

Separate delivery pipes 55, 51 are connected to each of the deliverypassages by packing nuts 59 and clamps 6I engageable with pairs of these`nuts are provided to prevent loosening thereof. Each of these twodelivery pipes leads from each pump cylinder to separate fuel injectors,not shown, adapted to be mounted in different working cylinders of aninternal combustion engine, not shown, for injecting fuel into thecylinder combustion chambers. The fuel by-pass or relief port 41 in eachpump cylinder sleeve I1 is connected by separate radially inwardlydirected passages 62. Eachof these passages opens into one of sixby-pass ports or relief ports 63 spaced circumferentially 60 degreesapart in the valve sleeve l5. The valve sleeve is also provided with adrain port 65 opening into an annular cavity 61 in the housing borearound this sleeve. A drain passage 69, shown in Figure 6, extendsradially outwardly from the cavity 61 and a pressure relief valve 10 isconnected to the outer end of the passage 51 to maintain a predeterminedpressure in this passage. The pressure relief valve discharge opening1|, indicated in Figure 2, is connected by a return pipe 12 to the fueltank.

A pump plunger 13 is mounted for reciprocation in each cylinder sleevel1. Each plunger, as best shown in Figure 1, is provided with an annulargroove 'l5 which registers with the by-pass port 41 in each pump sleevelI1 for all positions of the plunger. Connecting diametral and axialpassages 11, 19, provided in the plunger serve to connect the plungergroove with the pumping space 21 above the plunger. The plunger 13, asshown in Figure l, is at the lower end of the filling stroke with theupper end thereof covering the lower fuel delivery port 45 in the pumpcylinder I1. A rotary valve 8| in the sleeve l5 is driven in timedvrelation with the plungers 13 to prevent fuel flow through each by-passport 41 at two points in the upward stroke of each plunger to causedelivery offuel through the upper and lower delivery ports 44 and 45successively and to open the by-pass port prior to and subsequent toeach delivery to cause by-pass of fuel from and relief of pressure ineach pumping chamber 211. The valve is movable axially in the sleeve tovary the duration of delivery and when moved to another position causescontinuous bypass and, therefore, no delivery from the pumning chambers.

The rotary valve 8|, as best shown in Figures 1 and'9, is provided withan annular by-pass groove 83 in continuous register with the drain port85 in the valve sleeve for all axial positions of the valve. As bestshown in Figures 9 and 10 the valve is also provided with an undercutportion 85 adjacent the groove 83. This undercut portion extends 190around the valve and the same depth of the groove 83, as best shown inFigures 9 and 10. Lands LI and L2 are provided on the valve and areshown extending axially downward into the undercut portion 85. Each landis of identical shape. having inclined leadling and trailing edges 81and 89, respectively. The center lines of the lands Ll and L2 are spacedapart. The center line of the leading land 'Li is spaced 541/2? behindthe axial leading edge 80 of the undercut portion 85 and the axialtrailing edge 9| of the undercut portion is spaced 511/ behind thetrailing edge 89 of the trailing land L2. With the valve 8| in theuppermost position in the valve sleeve I5. as shown in Figure 1, thelower ends of the lands are iiush with the upper edges of the reliefports 63 in the valve sleeve and these ports are not covered by thelands when the valve is rotated so that bypass or relief of each pumpcylinder is continuous for 196 of valve revolution so that no fuel isdelivered by the plungers. This uppermost position of the valve isaccordingly, the no fuel delivery or engine stop position of the valve.I; will be evident that by moving the valve axially downwardly, theleading and trailing lands LI and L2 will close oif the by-pass` portseach 99 of revolution of the valve. Due to the helical edgeson the landsit will be evident that the farther the valve is moved downwardly in thevalve sleeve the earlier the relief or by-pass ports in the sleeve areclosed and, therefore, the earlier the start of fuel delivery by thepumps and also that the later the ports are opened or theA later thefuel delivery ceases. .In other words, the farther the valve is moveddownwardly the greater the amount of fuel is delivered at two points inits lift or pumping stroke as determined by closure of the relief orby-pass port by the leading and trailing valve lands LI and L2. Axialmovement of the valve 8l is accomplished by a gear 93 meshing with arack 95 supported for movement in the cap 3. The rack is operablyconnected to the upper end of the valve 8| by a coupling 91 whichpermits rotation of the valve relative to the rock. The gear 93 issecured to a control shaft 98 rotatably mounted in the cap. The controlshaft 98 is adapted to be connected lo either the engine governor or tomanual control means for varying the start and finish or fuel deliveryfrom the pump and accordingly the amount of fuel delivery therefrom intothe different engine cylinders connected to each pump.

The driving, lubricating and sealing means for the pump plungers, valveand operating means-V therefor is located in the lower housing 5. Thismeans includes a hollow driving shaft 99 rotat- 5 ably mounted inbushings and |03 supported in an axial bore in the lower housing and cap1.

A cam plate |05 for operating the plungers 13 is secured to the shaft 99and a ball thrust bearing v|01 is placed between the-cam plate 05 andlower cap 1. As will be subsequently described, the cam plate isprovided with cam surface |09 having a 172 lift followed by a 20 dwelland a 158 fall followed by a 10 dwell for operating plunger `camfollowers l. Each plunger cam follower is provided with a cam followerroller ||3 and the plunger is slidably mounted in a. bore in the lowerhousing 5 in alignment with a cylinder sleeve I1. A compression spring||5 is shown placed between the lower end of each cylinder sleeve and ashoulder on the lower end of each plunger 13 to urge it downwardly intocontact with the lower end of a counterbore in each cam follower to holdthe roller thereon in contact with the cam surface |09.

The valve 8| is driven in timed .relation with the cam plate by atorsionally resilient shaft |'|1 located within the hollow shaft 99 andsupported on an internal shoulder ||9 therein 'and connected by means ofa key |2| to the shaft 99.

The upper end vof the shaft I |1 has a hexagonal socket |23 securedthereto and a stub shaft |25 having hexagonal portions thereon, whichportions are engageable with the socket |23 on the y shaft ||1 andanother hexagonal socket.|21 secured in a recess in the lower end of thevalve 8|. The driving means for the valve comprising the resilient shaftand stub shaft and socket members provides a torsionally resilientcushion drive for the valve and permits misalignment between the valveand hollow shaft and also permits axial movement vof the valve withrespect to the lstub shaft |25 and valve sleeve I5.

The lower end of the hollow shaft 99 is provided with external splinesshown extending downwardly through a lubricating pump chamber |29provided in the lower housing cap 1 and outwardly through an opening ina closure member |3| secured to the lower cap 1 and forming the lowerface of the lubricating pump chamber. A driving gear |33 having aninternal spline is slidable on the lower splined end of the shaft 99 andis held thereon by a nut |35 threaded in the gear and slidable over thelower threaded end of the resilientshaft ||1 on which a nut |31 isthreaded to'hold the nut |35 in contact with the end of the l shaft. Anoil seal |39 is provided between a recess in the closure member and theouter surface of the hub of the driving gear to prevent oil leakagebetween these members.

The fuel pump and valve mechanism, described above, is oil pressurelubricated to prevent wear I andto prevent fuel leakage -and dilution ofthe lubricating oil. As best shown in Figure 5 an oil pump driving gear|4| is located in the lubricating pump chamber and splined on thedriving shaft 99. The gear I4| meshes with a pump idling gear |42rotatably mounted in the pump chamber |29. Connecting oil pressuresupply inlet passages |43, |45 and |41 for the pump chamber |29 areprovided in the'lower housing, lower cap and closure member,respectively, as best shown in Figures 5 and '1. A pressure outletpassage |49 is provided in the lower cap leading from the pump chamber|29 and an adjustable pressure regulating valve 5| is connected to theoutlet passage and is provided with a suitable by-pass passage |53,extendvalve 10 to the fuel return pipe 12.

passage |49. Connecting lubricating supply passages in the lower cap andhousing and upper cap indicated at |55, |51, |59, |5|, |53 and |55 leadfrom the lubricating pump pressure outlet passage to holes in the shaftbushings |8| and |03 and to the side wall of each plunger 13 and to thespace above the valve through a restricting orice |51. The upper andlower end surfaces of the valve 8| are shown' provided with externalhelical grooves for conveying oil from the ends of the valve toward theannular groove 83 in the valve. Leakage of oil from between the aboveparts falls by gravity on the cam follower guide'rollers i3, cam plate|05 and thrust bearing |01. Excess oil in the interior of the housing isdrained oir through an overflow or outlet opening |59 in the housing.as-best shown in Figure 8.

It has been found desirablel to supply oil under pressure to the inletpassage |43 in the lower housing from the engine oil pump and to connectthe overow 'opening |69 to the engine sump.

kyThe operation of the fuel injectionvpump is as follows: With theengine running fuel under pressure is supplied through the inlet pipe30- to the fuel cavity 28 and is directed by means of the baille 33 sothat any vapor is separated from the4 fueland the vapor and excess fuelis returned to the fuel tank through the return pipe 43 as previouslydescribed.

As previously explained the cam surface |09on Ithe cam plate |05 causesreciprocation of the plungers 13 and the valve 8| is connected to thecam plate by the torsionally resilient shaft I |1 for rotation thereby.

The operation of each pump is the same and the events occurring in onerevolution of the cam plate |05 and valve 8| occur at 60 intervals asthe axes of the six pumps are spaced 60 apart around the valve. Theoperation of each pump will be better understood by reference to thetiming dia.- gram shown in Figure 11. At the 0 line on the diagram theplunger is at the bottom of its filling stroke and fuel has entered andcompletely filled the pumping space 21 above the plunger through theunseating of the fuel inlet valve 23 due to the reduction in pressure inthe pumping chamber below that in the fuel cavity 29 in which any vaporltherein is separated and returned Ato the tank. It will be noted thatthe plunger reached the bottom of the filling stroke at the start of the10 dwell of the cam surface at the end of the fall of cam surface at the350 line of the diagram and that the valve relief port 63 was opened atpoint A or 356 lon the diagram by passage of the axial leading edge 90of the valve 8| past the port 53. Following the diagram in the clockwisedirection from the zero line, the lift of the cam surface causes upwardmovement of the plunger on the delivery stroke. As the by-pass or reliefport 53 of the valve is opened at this time, fuel will be by-passed fromthe pumping chamber 21 through the pump cylinder by-pass or relief port41, passage 62, valve sleeve by-pass or relief port 53 and past therelief portion 85 of the valve between the leading axial edge andleading land on the valveV and valve groove 83 and back to the fuel tankthrough the valve sleeve drain port 55, cavity 61 and passage 69, andpast the pressure relief By-pass of fuel from the pumping chambercontinues until the leading inclined edge 81 of the leading valve landLI closes olf the cylinder sleeve by-pass or relief port 63. vThisoccurs at point B or 38 on the diagram, with the valve in the lowestposition corresponding to the maximum fuel delivery poner the fueltrapped in the pumping space is then delivered under pressure by upwardmovement of the plunger through the upper cylinder delivery port 44causing the check valve 53 in the delivery passages 49 to be unseatedand delivery of fuel through the pipe 51 to the fuel injector in oneengine cylinder. Delivery and injection of fuel to this engine cylindercontinues as long as the leading valve land Ll covers the relief orbypass port in the valve sleeve. As shown in the diagram maximum fueldelivery through the upper cylinder port takes place with the valve inthe lowest position in which the earliest start and latest finish ofdelivery or injection occurs. Up-

ward movement of the valve retards the start and reduces the finish ofdelivery and no fuel is delivered when the valve lands are movedupwardly to prevent closure of the by-pass or relief port.

1 For maximum fuel setting of the valve the trailing edge 89 of theleading valve land Ll starts to uncover the valve by-pass or relief port63 at point `C or 63 on,the diagram to relieve the pressure inthe pumpchamber through the above described ports and passages in the valve, thehigh pressure being relieved to the fuel tank. It will be noted thatmaximum delivery of 25 of cam plate revolution is provided. Shortlyafter the opening of the by-pass port, at point D or 65 on the diagram,the plunger starts closing the upper delivery port 4,5 and at point E or83 on the diagram starts opening the lower delivery port 44. Furtherupward movement of the plunger causes by-pass of fuel to the fuel tankuntil the plunger closes the upper delivery port at point F or 108 onthe diagram and the inclined leading edge 81 of the valve trailing landthen closes off the valve bypass or relief port at point G or 128 on thediagram. This causes the fuel pressure to rise in the pumping chamberand the open lower delivery port to a value sufficient to unseat thecheck valve 53 in the delivery passages 44, 49 leading from the lowerdelivery port. Fuel is then delivered through this port and thesepassages through the plunger passages 11 and 19 and delivery pipe 55 toanother engine cylinder fuel injector. With the valve in the maximumfuel position delivery through the lower delivery port also continuesfor 25 of revolution of the cam plate or until the inclined trailingedge 89 of the trailing land L2 starts to uncover the by-pass or reliefport at point H or 153 line of the diagram. The pressure in the pumpcylinder is accordingly relieved in the same manner as previouslydescribed and fuel delivery or injection to the second engine cylinderceases.

On account of the 20 dwell following the lift of the cam surface theplunger is held in the upper end of the delivery stroke and is thencaused to be moved downwardly on the filling stroke by the spring H5,due to the fall in the cam surface beginning at point I or 192 on thediagram, at which point the axial trailing edge 9| of the valve closesoff the valve by-pass or relief port. The plunger in moving downwardlydecreases the pressure in the pumping chamber below the value maintainedin the fuel cavity and the fuel inlet valve 23 'is accordingly unseatedby this difference in pressure and fuel enters and completely fills thepump chamber. The filling stroke ends at the mark on the diagram aspreviously explained and the upper delivery port is opened at point J or260 and the lower delivery port is closed at point K or 268 on thediagram by this downward movement of the plunger on the filling stroketo complete the cycle.

I claim:

l. A fuel injection pump comprising a cylinder having an automatic fuelinlet valve, axially spaced delivery ports, and a fuel by-pass andrelief port spaced axially therefrom, a plunger reciprocable in thecylinder and having a control surface adapted to open and close eachdelivery port each stroke of the plunger, and a valve operated in timedrelation with said plunger and adapted to shut off said by-pass andrelief port during the inlet stroke of the plunger to cause opening ofthe fuel inlet valve and to open and close the by-pass or relief portduring the pumping stroke so that fuel is by-passed from the cylinderprior to and pressure is relieved subsequent to delivery of fuel througheach delivery port at different points in the delivery stroke of theplunger.

2. A fuel injection pump comprising a cylinder having a fuel inlet checkvalve, delivery ports and a by-pass and relief port spaced apartaxially, a plunger reciprocable in said cylinder and having a controlsurface adapted to uncover each delivery port each stroke, and a valverotating in timed relation with said plunger having a control surfaceadapted to close off the by-pass and relief port during the inlet strokeof the plunger to cause opening of the inlet Valve, said valve beingaxially movable relative to the by-pass and relief port and having landsprovided with inclined edges adapted to open and close said port duringthe delivery stroke of the plunger in order to control the amount offuel delivered through each delivery port.

3. A fuel injection pump including a fuel inlet cavity, inlet and returnopenings in the cavity and means in the cavity for directing andseparating vapor from the entering fuel and for causing the vapor topass out through the return opening, a pump cylinder having an inletcheck valve connected to the cavity, saidV cylinder having a pluralityof delivery ports and a relief port spacedapart axially, a plungerhaving a control surface adapted to open and close each delivery porteach stroke of the plunger, a valve rotated in timed relation with saidplunger and axially movable with respect to the relief port, said valvehaving a control surface adapted to close off the relief port during theinlet stroke of the plunger and valve lands having inclined leading andtrailing edges adapted to be moved axially with respect to the reliefport to close off said port for different in- A tervals of time duringthe pumping stroke of the plunger so vthat the amount of fuel deliveredthrough each delivery port may be accurately controlled.

4. A fuel injection pump including an inlet fuel cavity, a pressuresupply connection and a vent connection to said cavity, fuel flowdirecting means in said cavity between said connections to causeseparation of vapor from the entering fuel and to cause continuousventing of vapor from the upper portion of the cavity, a plurality ofpump cylinders, a fuel inlet connection including an inlet check valvebetween the fuel inlet cavity and each cylinder, each cylinder havingtwo delivery ports and a relief port spaced axially apart, a plungerreciprocable in each cylinder, each plunger having a relief groovecommunicating with the working face of the plunger, said grooveregistering with the relief port for all positions of the plunger andthe surface between the groove and working face adapted to open and:cylinder is opened by movement of a respective plunger at differentpoints in the delivery stroke in order to control delivery of fuel outof each cylinder delivery port.

5, A fuel injection pump comprising a housing having a fuel cavityprovided with fuel inlet and return openings, means in the cavity forchanging the direction of fuel flow between the cavity openings in orderto cause separation of vapor from the fuel and passage of vaporoutwardly through the return opening, a plurality of pump cylinders,each having an inlet check valve opening into the fuel cavity andseparate delivery ports and a relief'port spaced apart longitudinally, aplunger in each cylinder having a relief groove in continuous registerwith the relief port and communicating with the working face of theplunger, and a surface adiacent the working face, said surface and saidgroove cooperating with the delivery ports to cause each to be openedand closed each stroke of the plunger, means for reciprocating theplungers in timed relation, and a control valve rotatable in timedrelation .with the plungers and slidable axially in the housing, saidvalve having an undercut portion in register with a housing reliefpassage and control edges for opening and closing each of said cylinderrelief ports when each of said delivery ports are opened to control theamount of fuel delivery therethrough.

6. A fuel injection pump comprising a housing having a fuel cavityprovided with fuel supply l0y inder openings leading therefrom, eachcylinder opening having an inlet check valve therein, a perforatedbaille in the cavity for directing the fuel in different directions.to'cause separation of any vapor from the fuel and the return of vaporand fuel through the return opening, each of said cylinder openingshaving a plurality of fuel delivery ports and a relief port spaced apartlongitudinally, a plunger in each cylinder forming a pumping chamberadjacent the inlet valve and having a relief groove adjacent the workingface of the plungervregistering with the cylinder relief groove andpassages between the groove and face whereby each delivery port isopened each stroke of the plunger to the pumping space, a relief valve,rotatable and slidable axially in the housing, having an undercutportion provided with axially leading and trailing edges and leading andtrailing lands with inclined edges extending into the relief portion,said undercut valve portion communicating with a relief passage in thehousing, .including a pressure operated relief valve, said rotatablerelief valve communicating successively with each of said cylinderrelief ports when each of said delivery ports are opened to the cylinderpumping chamber, and means for moving said relief valve axially in thehousing to cause the valve lands to close each of said cylinder relief.ports for different intervals of time thereby controlling the start andfinish of fuel delivery from each of said cylinder delivery ports. l

passage of vapor outwardly through the returnopening, each of saidcylinder openings having axially spaced delivery ports and a reliefport, a plunger in each cylinder having a control surface and reliefgroove adJacent the working face and passages extending from the grooveand face, said surface and groove cooperating with the delivery ports tocause each to be opened and closed each stroke of the plunger, means forreciprocating the plungers in timed relation, a valve rotatable in timedrelation with the plungers and capable of axial movement in saidhousing, said valve having an undercut portion with axial and inclinededges cooperating with' each of saiddcylinder relief ports successivelyand with a relief passage in the housing when each of said cylinderdelivery ports are opened by movement of each of said plungers on thedelivery stroke to cause delivery of fuel through each of said cylinderdelivery ports, and means for displacing said valve axially in thehousing to present different'portions of the inclined control edges tothe cylinder relief ports in order to vary the start and finish ofdelivery and the amount of fuel delivered through each of said cylinderdelivery ports.

'l'. A fuel injection pump comprising a housing having a fuel cavityprovided with fuel supply and return openings anda plurality of pumpcyl- 8. A fuel injection pump comprising a housing having a fuel cavityprovided with fuel supply and return openings and a plurality ofcylinder openings, each cylinder opening having an inlet check valvetherein, a baiiie in the cavity for reversing the flow of fuel betweenthe inlet and return openings to cause separation of vapor from the fueland vpassage to vapor and fuel outwardly through the return opening,each cylinder opening having a plurality of delivery ports and a reliefport spaced apart axially, a -plunger in each cylinder forming a pumpingspace therein adjacent the inlet valve, each plunger having a reliefgroove adjacent the'working face registering with a plunger relief portand pas-- sages between the groove and the face adjacent the pumpingchamber so that each cylinder delivery port is opened to the pumpingchamber each` stroke, rotatable cam means for reciprocating the plungersin timed relation, a relief valve mounted for rotation land axialmovement in said housing equidistant from each cylinder opening,torsionally resilient telescopic driving means between said'cam meansandsaid valve,y

yplunger on the delivery stroke.

9. A fuel injection pump comprising a housing including a fuel cavityprovided with fuel supply and return passages, fuel delivery passages,a.

fuel relief passage including a pressure operated relief.valve, alubricating pump, and lubricating pressure passages including a pressurerelief valve and lubricating leakage and supply passages, a plurality ofcylinder openings including A l! inlet check valves communicating withthe fuel cavity and delivery ports communicating with the deliverypassages, and a relief port, a plunger in each cylinder cooperating withthe delivery and relief ports, a relief valve rotatable and axiallymovable in the housing cooperating with the cylinder relief ports and ahousing relief passage, means for driving the plungers, valve l2plungers, valve and valvel controlling means lubricating said drivingmeans before entering said lubricating pump.

RONALD C. GROVES.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 2,040,507 Terry May 12, 19362,135,247 Aikman Nov. l, 1938 2,193,612 Alden Mar. 12, 1940 2,223,757DillstrOm Dec. 3, 1940 2,306,364 Skaredoff Dec. 22, 1942 2,357,563

Truxell Sept. 5, 1944

